Superheater



SUPERHEATER Filed My' 19, 192e w. F'. KEENAN, JR

2 SheetsSheet 2 K ATTORNEY Patented Oct. 20, 1931 immer WALTERF. KEENAN,33.,.orzrELHA1vLivEW YORK ./xs'ssfixonj'fro FOSTER WHEELER e CORPORATION, OF NENV YORK,v N. Y.,

A. oonronarroivor Newy vom:v

eurem-maren Y AppucatinI-niea nay 19,;926. ,serial No. 110,100. i

The general obj ect -of the lpresent. invention is to provide improvements in constructionand arrangement of a superheater of the typefemployed inwater tube boilersl comprising looped orU-tubeelements swept over bythe heating gases after the latter havefirst passed over a portion of the boiler heating surface and are correspondingly cooled below the combustion chamberA temperature.v More specifically," the, object of thel invention is to provide an arrangement ofY U- tube superheater elements adapted to the restricted spacial conditions-of water tube boilers, and characterized by the arrangementr of the sup-erheater .elements in banks separated by a-space into which elements from either bank can be readily removed without interference with other elements, -in effecting replacement of elements, and in which space soot blower elements may be so disposed as to secure a satisfactory coverage of thesuperheater elements by thev cleaning ets'discharged by the ysoot blowing elements 'which are accessible for inspection.v and repairs. The arrangement of the superheater elements in spaced apart banks permits of improvements in the superheater supporting provisions, andi in particular permits thelower superheater elements located in arelatively high temperature Zone to be readilycarried by water cool'edi supports, i. le. the boiler water tubes, while the upper supefrheated elements located in a cooler zone maybe carriedon ordinary steel and cast iron,` supports. The separation of the superheater elements into separately supported banks reduces the weight which kmust be impressed upon anyone set of supports.

VThe various features ofnovelty which characterize my invention are pointed -out with particularity in the claims annexedfto and forming a part ofV this specification. For a better understanding of the invention, however, its yadvantages and' specific objects attained with its use, reference should be had to the accompanyingfdrawings and descriptive matter in which I have illustrated and described preferred embodiments of my invention. j

Of the drawings: Fig. l is a vertical section;

2-is a partial section on the line 2 -2 Fig. 3 is a view taken similarly to Fig. l, illustrating a modified construction; and

Fig-4 is a partial section taken-similarly to Fig. 1 but on a larger scale. v In Figs l and 2 I have illustrated the use of my invention in a superheater boiler A of theso-called drop-bank, cross drum,horizon tal water tube type, with the superheater B located between theupper and lower banks of water tubes A with itsvheat absorbing sur- 'face' at the high vtemperature side of the transverse bailie C. The latter extends across the-upper bank of water tubes and the space betweenthetwo banksfrom'the upper end of the longitudinal baffle C which'rests on top of thelower bank of water tubes and extends from thek lower ends of the latter for a distance of something like half the length of the water tubes. f

i The superheater B, asV shown in Figs. 1 and 2, comprises an upper'inlet header B and a 'lower outlet header B2. The headers B and B2 are horizontal and transverse to the'water tubes, and are located adjacent the top and lthe bottom respectively, of the space between the two banks of water tubes, and adjacent to,

and at the low temperature side of the baflie C. .r The superheater Uv-tubefel'ement's 'have their legs generally parallel to lthe water tubes A', and are arrangedto. form'two .spaced apart banks located one adjacent 'the` top, and the other adjacent the bottom of the inter-deck space of the boiler. As shown, the

lower bank is vformed by a single row of U: tube elements B3', while the upper bank of superheater elements comprises two sets of elementsB4 andB, the elements B4 having their legs spread far enough apart to straddle the row of elements B5. The various elements B3, B4, and B5 may be all alike in form, and advantageously though not necessarily, Y I

header B2, while the lower end of the upper leg of the element is connected to the lower end of a corresponding vertical header B6.

The lower end of one element B4 and of one y element B5 are connected to the upper end of each header B6. With this arrangement the steamfow through each header B6 passes in a single stream through the corresponding element B3 and in divided streams through the corresponding elements B1 and B5. Y This givesra higher stream velocity intheportion f of thesuperheater where the steam and gas temperatures arev relatively high than in the portion of the superheater where-the steam somewhat desirable though the attainment of general advantages vof my invention does not depend on the number of sets of elements in either bank. j u

As shown, thelelements Bf are-supported adjacent their free ends and at points intermediate their ends by supporting Vprovisions including channel barsD and D, and vspacers 4cl extending transversely to the elements.

\ the manner disclosed in my prior Patent No.

With the space between the upper and .lower banks shown and described, superheater elements from Aeither bank may readily be moved into and throughsaid spacein remov- Ving old, and Vinstalling' new elements. Ad-

vantageously sadspace is wide enough to receive a workman, who may enter `the space vthrough normallyV closed manhole openings A2 in the side walls of the boiler, and thereby facilitates inspection and repair operations.

The separation of the superheater elements Y into upper and lower banks as described, proy the. superheater elements.

`ment also permits ready `access to the bearvides a spacerin which soot blower tubes F may be disposed as shown, so that the iets of icleaninguid discharged bythem will efectivelyclean practically all portions of This Varrange- VingsF for the soot blower tubes F vwhen the latter are of the well knownrotatable tube type shown. The soot blower tubes F advantageously extend transversely to water tubes, with kthe intermediate bearings F. for the sootJ blower tubes F attached to adj acent superheater elements in the usual manner. The arrangement of the soot blower tubes F above rather than below the lower bank of superheater elements as shown, is advantageous becauseof the resultant decrease in the temperatures to which the soot blower tubes are subjected. l

, The reduction of the weight of the portion of the superheater which must be supported by any one set of supporting provisions, and in particular which must be supported by any one set or row of boiler water tubes is of practical importance and permits of the use of an extent of superheating surface and length of superheater path of Vsteam flow greater than would otherwise be practically feasible in some superheater boiler inst-allations.' and gas temperatures are lower which is The inventionis not limited to use in a Vdrop bank boiler with the superheater located in the inter-deck space, butmay be employed whenthe .superheater is located in the more usual positionabove the water tubes as shown in Fig. 3. The superheater shown in Fig. 3 is `practically'identical in form with'that shown in Figs. l and 2, butin Fig. 3 the superheater is located in the space above the inclined water` tubes and thev superheater elements have portions of their lengths at each side of the y'transverse baiile C and the extension C2'thereot`. In Fig. 3 the superheater headers are shown as located at the low temperature side of the balile C34 which forms one side wall-of the final heating gas pass of the boiler. The lower. superheater elements B3 are shown in Fig. 3 as supported by the water tubes A3 beneath them as are the elements B3 in Figs. l and 2.y The elements B4E and -Biof Fig. 3 are supportedbyvbeams D2 Vand D3 and hangersE `and E- as shown in Fig. l, and by an additional supporting beam D? and set of hangers E4.. In the type of boiler-shown iin Fig. 3;, manholes A2 are advantageously provided at the'free end of, and above the upper bank of superheater elements, as well as between the two banks of superheater elements, andsoot blower tubes F may well be provided above the `upper bank of superheater elements as well as between the two banksof elements. 1

l', While in accordance with the provisions of the statutes, I have illustrated the best forms of my invention new known to me, it will be `apparent to those skilled in the art that changesy may be madeinthe'form. of the apparatus disclosed without departing from the spirit of my invention, asset forth Vin the appended claims, and` that certain features lof my invention may sometimes be used to advantage without a corresponding use of other features. Y

Having now described my invention, what I claim as new and desire to -secure lby Letters Patent is: I f 4vl. In a superheater boiler, a superheater comprising two banks of superheater elements separated by a space sufficient to permit the entrance of a workman between said banks for inspection and repairpurposes and adapted to receive elements from either bank without interference with elements in the .other bank, and soot blower tubes transversely mounted in said space and supported from one of said banks and adapted to discharge cleaning fluid jets against said elements.

' 2. Ina boiler, the combination with a bank of water tubes, of a superheater located above f said water tubes and comprising a bank of superheater elements supported by said water tubes and a second bank of superheater elements above and spaced away from the first mentioned bank of superheater elements, and means independent of said water tubes for supporting said second bank ofsuperheater elements.

3. A superheater comprising a bank of headers transverse to the elements each connecting one leg of a corresponding element in the first mentioned bank to adjacent legs of two elements in the second mentioned bank,

and inlet and outlet headers to which the` other legs of the elements in the two banks n ar-e connected. s

Signedv at New York city, in the county of New York, and State of New York, this 18th day of May, A. D. 1926. f 1 j WALTER F. KEENAN, lJn.

looped tube superheater ele-ments, a second s and comprising a lowerfbank of superheater f elements supported by the water tubesri'n the lower bank, and an upper bank of superv heater tube elements spaced away from the lower bank of elements and supported independently of the lower bank Vof water tubes.

5. The combination with a horizontal water tube boiler having upper and lower banks of water tubes, of a superheater located in theL space between the banks of water tubes and comprising a lower bank of superheater elements supported by the water tubes in the lower bank, and an upper bank of superheater tube elements spaced away from the lower bank of elements and supporting provisions for the upper bank of superheater elements extending into contact with and cooled by the upper bank of water tubes.

6. The combination with a horizontal water tube boiler having spaced apart upper and lower water tubes, of a superheater located in the spacevbetween saidl upper and lower water tubes and comprising a lower and an upper bank of superheater elements and soot blower tubes extending between saidbanks, the latter being spaced apart suiliciently to permit the entrance of a workman between said bank for soot blower ini spection and repair purposes.

7. A superheater comprising a bank of U- y tube superheater elements, a secondbank of U-tube superheater elements generally parallel to the first mentioned row of elements and laterally displaced therefrom, elongated 

